This seems to be related to a wrong order of installations. I detected a lot of corruptions at the IIS Web Service extensions level, but not from the interface, but from the command line which detects a little bit more and gives us more information. I was able to match the model of our test, development and actual production environments by removing and adjusting a few things.

I am applying now the proper order of installations of the .NET Framework and going step by step to see how they will be tied into IIS.